Slip ring is responsible for connecting to the rotating body, the transmission of energy and signal electrical components. According to the transmission medium to distinguish, slip ring is divided into electric slip ring, fluid slip ring, smooth ring. It can also be popularly referred to as "rotational connectivity" or "rotational connectivity". The slip ring is usually installed in the rotating center of the equipment, which is mainly composed of two parts: rotation and static. The rotating part connects the rotating structure of the device and rotates with it, called the "rotor", while the stationary part connects the energy of the fixed structure of the device, called the "stator". The whole slip ring depends on the principle of elastic lapping, rolling lapping, or sealing principle, as well as the ingenious motion structure and sealing structure design, precise parts production, reasonable material selection, etc., to form a stable and reliable rotating connected system. As long as the slip ring is attached to the equipment of infinite rotation, it can provide power energy to the rotating body, so that the rotating body can also carry out other movements or detect the working condition under the rotating state.